Muzzle thread and spigot details

The usual reflex suppressor muzzle thread and spigot detail is a metric thread (M14x1, M15x1, M17x1 or M18x1) with a long cylindrical “spigot” (F) and a relief cut (G) between the thread (H) and the shoulder (E) – see drawing. The purpose of the muzzle spigot (F) is to ensure precise alignment in conjunction with the close-fitting barrel bush at the rear of the suppressor.